The Mets have gotten a much-needed spark from the trio of prospects who have come up this season: Francisco Alvarez, Brett Baty and Mark Vientos.

But make no mistake, the offense is still driven by Pete Alonso.

That was on display again in Friday’s 10-inning, 10-9 win over Cleveland, a comeback sparked by Alonso’s game-tying grand slam in the bottom of the seventh.

It was the first baseman’s fourth straight game with a home run — giving him an MLB-best 17 on the season — and, not coincidentally, has led to wins in the Mets past three games.

“I’m just putting up the best at-bats I can,” Alonso said. “I’m trying to be on time, be in rhythm and capitalize on pitches over the heart of the plate and hit them hard. I’m happy they’re going over the wall and helping us win. I’m not ever gonna complain about that.”

Neither are the Mets, who have relied so desperately on Alonso’s power this season — something they’re hoping to do less as the season progresses and they look for more extra-base hits from the offensive-minded rookies.

As the Mets got themselves back to .500 after the season looked like it might be starting to slip away, no bat was more important than Alonso.

He leads the majors in homers, and each of his past four hits have been home runs.

On the flip side, there haven’t been a ton of other hits. Alonso has just one multi-hit game since April 21 — and none since April 27.

In that 25-game stretch from April 21 through Friday’s win, Alonso is just 16-for-90, but nine of those hits have been for extra bases. He’s also walked 12 times with 23 strikeouts.

But it’s been the past four games in which Alonso has really left his mark, with the four blasts and 10 RBIs.

The game-winner in the bottom of the 10th against the Rays on Wednesday started the current winning streak, and Alonso was just as emotional rounding the bases after his grand slam Friday.

“Earlier in the game, I had great swings, but didn’t end up with anything,” Alonso said. “I had no hits. The next pitch, the next at-bat, you just keep fighting, and you never know when that one swing comes and you change the game.”

It helped Alonso makeup for his blunder that ended the fifth, when the Mets were still trying to come back.

Having already scored twice in the inning and with Jeff McNeil at first, Alonso hit a soft liner to ex-Met Amed Rosario at shortstop.

Rosario dropped the ball, but Alonso didn’t run out of the box and was thrown out at first to end the inning.

Alonso called the play “very stupid on my part” and “bad baseball.”

Two innings later, Alonso homered to tie the game then further impacted the outcome with a fine diving play to his right on a grounder by Jose Ramirez.

Alonso flipped to David Robertson at first to end the top of the ninth to keep the game tied.

It’s the home runs, though, that set Alonso apart, and his walk-off shot versus Tampa Bay will no doubt be credited as starting the turnaround if the Mets keep it up.

“It’s not one moment,’’ Alonso said of why the team is playing better. “It’s a buildup of a bunch of different things. We’ve been fighting and grinding. We’ve earned every bit of it.”